Hole Saw with Open End Cap Geometry

ABSTRACT

A tool, such as a hole saw, including an open end cap geometry is provided. The end cap includes spokes extending between a hub and a rim. A plurality of openings are defined between the spokes, hub and rim. The area of the openings is substantially large relative to the area of the end cap such that the end cap is relatively lightweight and provides access into the hole saw for debris removal. The spokes are shaped and positioned to provide strength to the end cap.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

The present application is a continuation of U.S. application Ser. No.16/721,014, filed Dec. 19, 2019, which is a continuation of U.S.application Ser. No. 15/366,420, filed Dec. 1, 2016, which claimspriority to U.S. Provisional Application No. 62/264,605, filed. Dec. 8,2015, which are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of tools. Thepresent invention relates specifically to a tool, such as a hole saw,having an open end cap geometry. In general, a hole saw includes acylindrical structure with cutting teeth at one end of the cylinder. Inuse, the hole saw spins at a high rate of speed, cutting a hole in awork piece that has a size and shape that generally matches the size andshape of the cylindrical structure.

SUMMARY OF THE INVENTION

One embodiment of the disclosure relates to a tool, specifically a holesaw, including a body, such as a cylindrical saw body, and an end cap.The saw body includes a cutting edge at a first end of the saw body, anda second end of the saw body is coupled to an outer section of the endcap. The end cap includes a plurality of spokes extending radially froma central hub to the outer section. The end cap includes a plurality ofopenings defined between the spokes. In various embodiments, theopenings account for a substantially large portion of a total area ofthe end cap. In various embodiments, the portion of the total area ofthe end cap occupied by the openings decreases the overall weight of theend cap. In various embodiments, the openings are substantially largeproviding an access point for debris removal.

In various embodiments, each of the spokes includes a concave curvedclockwise-facing surface and a convex counterclockwise-facing surface.In various embodiments, the end cap includes at least four spokes.

In various embodiments, the openings are sized such that at least 10% ofthe total end cap area is occupied by the openings. In variousembodiments, the openings are sized such that at least 30% of the totalend cap area is occupied by the openings. In various embodiments, theopenings are sized such that at least 60% of the total end cap area isoccupied by the openings.

In various embodiments, the ratio of the area of the openings to thearea of the solid portions of end cap is between 0.15 and 2. In variousembodiments, the ratio of the area of the openings to the area of thesolid portions of end cap is between 0.15 and 0.45. In variousembodiments, the ratio of the area of the openings to the area of thesolid portions of end cap is between 0.3 and 0.7. In variousembodiments, the ratio of the area of the openings to the area of thesolid portions of end cap is between 1 and 2.

Another embodiment of the disclosure relates to a hole saw. The hole sawincludes a cylindrical body having a first edge located at a first endof the cylindrical body and a second edge located at a second endopposite the first end. The hole saw includes cutting teeth extendingfrom the first end of the cylindrical body. The hole saw includes an endcap coupled to the second end of the cylindrical body. The end capincludes a hub and a plurality of end cap openings located radiallybetween the hub and an outer perimeter edge of the end cap. Theplurality of end cap openings occupy a relatively large portion of thearea of the end cap, and the relatively large portion is at least 10% ofthe area bounded by the outer perimeter edge of the end cap. The holesaw includes an arbor configured to couple the hole saw to a drivingtool, and the arbor is coupled to the hub and extends outward from theend cap in a direction opposite from the cutting teeth.

Another embodiment of the disclosure relates to a hole saw. The hole sawincludes a cylindrical body having a first edge located at a first endof the cylindrical body and a second edge located at a second endopposite the first end. The hole saw includes cutting teeth extendingfrom the first end of the body. The hole saw includes an end cap coupledto the second end of the body. The end cap includes a central hub and anouter perimeter edge coupled to the second edge of the cylindrical body.The end cap includes at least four spokes extending radially outwardfrom the central hub toward the outer perimeter edge and a plurality ofopenings defined within the end cap. Each of the plurality of openingsis located between an adjacent pair of spokes.

Another embodiment of the disclosure relates to a reduced weight holesaw. The reduced-weight hole saw includes a body having a first end anda second end opposite the first end and cutting teeth extending from thefirst end of the body. The reduced-weight hole saw includes an end capwhich is coupled to the second end of the body and which has an outeredge surrounded by and coupled to the second end of the body. Thereduced-weight hole saw includes an open area defined in the end cap,and the open area extends between upper and lower surfaces of the endcap such that access through the end cap to an interior of the body isprovided by the open area. The open area has a first area and the uppersurface of the end cap has a second area, and the first area is between20% and 70% of the second area.

Additional features and advantages will be set forth in the detaileddescription which follows, and in part will be readily apparent to thoseskilled in the art from the description or recognized by practicing theembodiments as described in the written description and claims hereof,as well as the appended drawings. It is to be understood that both theforegoing general description and the following detailed description areexemplary.

The accompanying drawings are included to provide a furtherunderstanding and are incorporated in and constitute a part of thisspecification. The drawings illustrate one or more embodiments andtogether with the description serve to explain principles and operationof the various embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a hole saw, according to an exemplaryembodiment.

FIG. 2 is a top plan view of an end cap of a hole saw, according to anexemplary embodiment.

FIG. 3 is a top plan view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 4 is a perspective view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 5 is a perspective view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 6 is a perspective view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 7 is a perspective view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 8 is a top plan view of an end cap of a hole saw, according toanother exemplary embodiment.

FIG. 9 is a top plan view of an end cap of a hole saw, according toanother exemplary embodiment.

DETAILED DESCRIPTION

Referring generally to the figures, various embodiments of a hole cutteror hole saw including an open end cap design are shown. In general, ahole saw includes a cylindrical sidewall, a cutting end having cuttingteeth at one end of the cylindrical sidewall and an end cap at the otherend of the cylindrical sidewall. As will be generally understood, theend cap includes a mounting structure that mounts to a driving device(e.g., a power tool) that drives the hole saw in rotation to cut a holein a workpiece. In various embodiments, the end cap of the hole sawdiscussed herein includes an open design or end geometry in which asubstantially large portion of the area circumscribed about theperimeter of the end cap (e.g., at least 10%, at least 20%, at least50%, at least 60%, etc.) are occupied by openings that extend betweenopposing upper and lower surfaces of the end caps. In at least someembodiments, the end caps discussed herein include spokes extending froma central mounting hub radially outward to a circumferential rimdefining the outer perimeter of the end cap. The rim is coupled to thecylindrical sidewall.

In various embodiments, it is believed that the open end cap geometrydiscussed herein provides a number of improved functional advantages notfound in conventional hole saws that include closed end caps or end capswith relatively small openings. In various embodiments, it is believedthat the open end cap geometry discussed herein lowers the amount ofmaterial needed and weight of the end cap without decreasing hole sawcutting performance or the ability of the end cap to transfer power fromthe driving tool to the cutting edge of the saw. In some embodiments, itis believed that the open end cap structure discussed herein providesbetter access into the interior of the hole saw which facilitates debrisremoval, for example during cutting. In some embodiments, improved endaccess may operate in conjunction with side access to allow for easierdebris/plug removal after cutting. Further, in some embodiments, theopen end cap design provides improved air flow into the interior of thehole saw during cutting. In some embodiments, the lower weight end capdiscussed herein decreases the moving mass of the tool which improvesbattery life/decreases power usage and which also reduces wear and tearon various moving parts of the tool, such as gears, for example when thetool stops. In some embodiments, the reduced weight provides variousmanufacturing advantages due to handling of a lighter weight pieceand/or new formation methods made available by the open end cap design.Further decreasing the overall weight and material used in the end capalso decreases the material cost of the component.

In particular embodiments, Applicant has identified a curved spokedesign in which the outer surfaces of spokes curve or arc in thedirection of cutting rotation, such that at least a portion of thespokes experience compressive forces during cutting without experiencingany significant tensile forces during cutting. Applicant believes thatsuch design allows for the inclusion of the large end cap openingsdiscussed herein while providing sufficient strength for high-poweredcutting operations. As disclosed herein, Applicant has identified anumber of particular end cap design configurations that Applicantbelieves provide one or more of the various improved functions discussedherein while also providing a sufficient strength and support for thehole saw during cutting. In various embodiments, in contrast toconventional manufacturing methods that form conventional end caps froma solid sheet of material, the open end cap design discussed hereinenables the use of a variety of methods including powder metallurgy,investment casting, metal injection molding, metal stamping, etc. whichopens up new manufacturing processes and efficiencies compared toconventional manufacturing methods. Thus, in various embodiments, theopen end cap design discussed herein provides a combination of potentialcost savings stemming from the availability of new manufacturing methodsfor end cap formation.

Referring to FIG. 1, a hole saw, such as hole saw 10, is shown accordingto an exemplary embodiment. Hole saw 10 includes a cylindrical body 12including cutting end 14 at a first end of body 12 and an end cap 16coupled to the opposite, second end of body 12. In general, end cap 16is a disc of metal material (including one or more of the variousopening or spoke configurations discussed herein) that may be coupled tobody 12 via a coupling structure such as a weld. In various embodiments,end cap 16 includes a central mounting portion for coupling to a toolattachment structure, shown as arbor 18. As will be generallyunderstood, arbor 18 facilitates coupling of hole saw 10 to a drivingdevice (e.g., an impact driver, power drill driver, etc.) which driveshole saw 10 during cutting.

As shown in FIG. 1, cutting end 14 includes a plurality of teeth 20 thatextend around cutting end 14. Teeth 20 may be formed in a wide varietyof designs for different cutting applications. Further, cylindrical body12 is a substantially hollow cylinder defining a hollow internal area 22bounded by inner surface 24 of body 12. As will be explained in moredetail below, the open geometry of the end cap embodiments discussedherein provide additional access points through the end cap tofacilitate removal of cutting debris from internal area 22.

Further, as shown in FIG. 1, hole saw 10 defines a longitudinal axis 26that extends lengthwise through hole saw 10, perpendicular to end cap 16and perpendicular to a plane defined by cutting end 14. Further, holesaw 10 includes a center of gravity 28 located along the length oflongitudinal axis 26. Because of the open end geometry of end cap 16(discussed in more detail below), center of gravity 28 is shiftedfurther along longitudinal axis 26 toward cutting end 14, as compared toa hole saw with a heavier end cap, a closed-off end cap, or an end capwith smaller/fewer end cap openings.

Referring to FIGS. 2-9, various embodiments of an end cap for a hole saware shown. It should be understood that, generally, any of the end capembodiments discussed herein may be the end cap 16 of hole saw 10 asshown in FIG. 1.

Referring to FIG. 2, a hole saw end cap 30 is shown according to anexemplary embodiment. In general, hole saw end cap 30 is a solid, rigidstructure including a central hub 32, a first pair of spokes 34, asecond pair of spokes 36 and an outer section, shown as outer rim 38. Ingeneral, hub 32 includes a central hole 33 for receiving an arbor and aplurality of drive pin holes 35 for receiving the drive pins of thearbor. Spokes 34 and 36 extend radially outward from hub 32 toward rim38. As will be generally understood, one end of hole saw body 12 (shownin FIG. 1) is mounted to a lower surface of rim 38. It should be notedthat in the embodiment shown, outer rim 38 is a contiguous circularstructure defining a circular outer edge or perimeter of end cap 30.However, in other embodiments (see FIG. 9 below), the outer section ofend cap 30 may be discontinuous such that gaps are located along theouter perimeter of end cap 30.

In various embodiments, hole saw end cap 30 includes a plurality ofinner surfaces that define a plurality of openings boundedcircumferentially by rim 38. In the particular embodiment shown, holesaw cap 30 includes a first pair of openings 40 and second pair ofopenings 42. In general, openings 40 and 42 are through-bores extendingbetween opposing upper and lower surfaces of end cap 30 such that accessis provided into the interior of hole saw body 12 through openings 40and/or 42. Such large openings may advantageously allow debris to bepushed out of hole saw 10 through the large opening circumscribed bycutting end 14. It is believed that, in at least some embodiments, thelongitudinal pushing direction enabled by openings 40 and 42 allow foreasier debris removal compared to some side wall opening designs.Further, it is believed that the large openings 40 and 42 may provideimproved airflow within hole saw 10 during cutting.

In the embodiment shown, openings 40 have a different size and shapethan openings 42, and specifically openings 40 are smaller than openings42. Hole saw end cap 30 is formed such that each opening 40 is amirror-image of the opposing opening 40 relative to the center point ofend cap 30 and that each opening 42 is a mirror image of opposingopening 42 relative to the center point of end cap 30. In the particularembodiment shown, while openings 40 and 42 form mirror images of eachother, openings 40 and 42 and spokes 34 and 36 define an end cap patternthat is not radially symmetric.

As shown in FIG. 2, openings 40 and openings 42 account for asubstantially large portion of the area of hole saw end cap 30. Inparticular embodiments, the outermost edge or perimeter of rim 38defines or circumscribes a total end cap area, and the total end caparea is the sum of the area of all of the solid components of end cap 30(e.g., hub 32, spokes 34 and 36 and rim 38), of openings 40 and 42 andof the areas of the mounting openings within hub 32. In one embodiment,the area of openings 40 and 42 is at least 10% of the total end caparea. In another embodiment, the area of openings 40 and 42 is at least30% of the total end cap area. In another embodiment, the area ofopenings 40 and 42 is at least 60% of the total end cap area. In anotherembodiment, the area of openings 40 and 42 (e.g., the total open area ofend cap 30 excluding openings 33 and 35) is greater than 20% and lessthan 70% of the total end cap area.

In particular embodiments, the area of openings 40 and 42 is between 15%and 35%, specifically between 20% and 30%, and more specifically between20% and 25% of the total end cap area, and in one such specificembodiment, the diameter of end cap is between 2 and 3 inches andspecifically is about 2.5 inches. In other particular embodiments, thearea of openings 40 and 42 is between 20% and 50%, specifically between30% and 40%, and more specifically between 33% and 37% of the total endcap area, and in one such specific embodiment, the diameter of end capis between 3 and 5 inches and specifically is about 4 inches. In otherparticular embodiments, the area of openings 40 and 42 is between 40%and 80%, specifically between 50% and 70%, more specifically between 60%and 70%, and even more specifically between 61% and 65% of the total endcap area, and in one such specific embodiment, the diameter of end capis between 5 and 7 inches and specifically is about 6 inches.

In various embodiments, the substantially large openings 40 and 42 canbe defined by the ratio of the area of openings 40 and 42 to the area ofthe solid portions (e.g., hub 32, spokes 34 and 36 and rim 38) of endcap 30. In various embodiments, the ratio of the area of openings 40 and42 to area of the solid portions of end cap 30 is between 0.15 and 2 andmore specifically between 0.25 and 1.7.

In particular embodiments, the ratio of the area of openings 40 and 42to area of the solid portions of end cap 30 is between 0.15 and 0.45,specifically between 0.25 and 0.4, and more specifically between 0.3 and0.35 of the total end cap area, and in one such specific embodiment, thediameter of end cap is between 2 and 3 inches and specifically is about2.5 inches. In other particular embodiments, the ratio of the area ofopenings 40 and 42 to the area of the solid portions of end cap 30 isbetween 0.3 and 0.7, specifically between 0.4 and 0.6, and morespecifically between 0.5 and 0.6 of the total end cap area, and in onesuch specific embodiment, the diameter of end cap 30 is between 3 and 5inches and specifically is about 4 inches. In other particularembodiments, the ratio of the area of openings 40 and 42 to the area ofthe solid portions of end cap 30 is between 1 and 2, specificallybetween 1.4 and 1.8, and more specifically is between 1.55 and 1.75 ofthe total end cap area, and in one such specific embodiment, thediameter of end cap is between 5 and 7 inches and specifically is about6 inches.

Still referring to FIG. 2, in various embodiments, openings 40 and 42are substantially large compared to the coupling openings (e.g.,openings 33 and 35) located within hub 32. In specific embodiments, thearea of end cap 30 occupied by openings 40 and 42 is at least five timesthe area occupied by coupling openings 33 and 35, and more specificallythe area of end cap 30 occupied by openings 40 and 42 is at least tentimes the area occupied by coupling openings 33 and 35.

In various embodiments, openings 40 and 42 allow for end cap 30 to havea lower weight than that of a solid end cap or an end cap withsmaller/fewer holes (at least for a given material type). In variousembodiments, end cap 30 weighs between 0.1 lbs. and 1 lbs., andspecifically between 0.2 lbs. and 0.8 lbs. In specific embodiments, theopen end cap design discussed herein decreases the total end cap weightby between 40% to 80% as compared to a substantially closed,conventional end cap of the same diameter, and as noted above, suchweight savings provide technical advantages including decreased powerusage, improved battery life and decreased component/gear wear duringusage and/or stopping.

In particular embodiments, as shown for example in FIG. 2, openings 40and 42 are defined by interior surfaces of spokes 34 and 36 and of rim38 such that the shapes of these surfaces define the shapes of openings40 and 42. In various embodiments, it is believed that the number andshape of spokes 34 and 36 and the resulting shapes of openings 40 and 42allow for spokes (particularly the radially outer surface of each spoke)to remain in compression (i.e., experiencing little or no tension)during clockwise rotation as experienced during cutting. It is believedthat by maintaining these portions of spokes 34 and 36 in compressionduring cutting, end cap 30 is strengthened. It is believed that bylimiting or eliminating the tensile forces that spokes 34 and 36 mayexperience, the strength of end cap 30 is increased, at least relativeto spoke designs that experience tension.

In general, end cap 30 includes at least four spokes, shown as spokes 34and 36. As shown in FIG. 2, spokes 34 and 36 are generally curved in theclockwise direction. Similar to the shape of openings 40 and 42discussed above, each spoke 34 is a mirror image of the opposing spoke34, and each spoke 36 is a mirror image of the opposing spoke 36. Inother embodiments, end cap 30 includes other numbers of spokes. Inspecific embodiments, end cap 30 includes two spokes.

As shown in FIG. 2, each spoke 34 includes clockwise-facing surface 44and counterclockwise-facing surface 46. In this arrangement,clockwise-facing surface 44 is a concave surface, andcounterclockwise-facing surface 46 is a convex surface. Further, thelength of counterclockwise-facing surface 46 is greater than the lengthof clockwise-facing surface 44. In various embodiments, the length ofcounterclockwise-facing surface 46 is at least 10%, and specifically25%, greater than the length of clockwise-facing surface 44. In specificembodiments, such as shown in FIG. 2, the length ofcounterclockwise-facing surface 46 is at least 60% greater, andspecifically at least 180% greater than the length of clockwise-facingsurface 44. In some embodiments, the lengths in the radial direction ofat least one counterclockwise-facing surface 46 and clockwise-facingsurface 44 is relatively large compared to the radius of end cap 30. Inspecific embodiments, the lengths in the radial direction of at leastone counterclockwise-facing surface 46 and clockwise-facing surface 44is at least 50% of the radius of end cap 30.

Similar to the shape of spokes 34, each spoke 36 includesclockwise-facing surface 48 and counterclockwise-facing surface 50. Inthis arrangement, clockwise-facing surface 48 is a concave surface, andcounterclockwise-facing surface 50 is a convex surface. Further, thelength of counterclockwise-facing surface 50 is greater than the lengthof clockwise-facing surface 48. In various embodiments, the length ofcounterclockwise-facing surface 50 is at least 10%, and specifically25%, greater than the length of clockwise-facing surface 48. In specificembodiments, such as shown in FIG. 2, the length ofcounterclockwise-facing surface 50 is at least 30%, and specifically65%, greater than the length of clockwise-facing surface 48.

In addition to the shapes discussed above, in the embodiment of FIG. 2,the portions of each spoke 34 and 36 adjacent to hub 32 is wider thanthe portions of spokes 34 and 36 adjacent rim 38. For example, in thisarrangement, the center of mass of each spoke 34 and 36 is closer to thecenter point of end cap 30 than to the outer perimeter of rim 38.

Further, openings 40 and 42 each have a non-symmetrical shape. In theembodiment shown in FIG. 2, each opening 40 has a width, W1, and eachopening 42 has a width, W2. As shown in FIG. 2, both W1 and W2 decreasein the circumferential clockwise direction. This relationship givesopenings 40 and 42 the somewhat pointed appearance shown in FIG. 2. Inaddition, each spoke 34 and 36 has a maximum dimension in thecircumferential direction that is less than the maximum dimension in thecircumferential direction of either opening 40 or opening 42.

As shown in FIG. 2, the radially outermost edge of opening 40 is definedby a radially inward facing edge 52 of rim 38, and the radiallyoutermost edge of opening 42 is defined by a radially inward facing edge54 of rim 38. Edges 52 and 54 are aligned curved surfaces such thatedges 52 and 54 have the same radius of curvature and same center pointas each other and therefore lie in the same circular path as each other.

Inner edges 52 and 54 are defined by radius, R1. The outer edge of rim38 and the outer radius of end cap 30 is defined by the radius, R2. Invarious embodiments, the difference between R1 and R2 (which alsocorresponds to rim 38 thickness at the position of openings 40 and 42)is relatively low which relates to the increased size of openings 40 and42. In various embodiments, R1 is between 50% and 99% of R2,specifically between 65% and 99% of R2 and more specifically between 70%and 95% of R2. In a specific embodiment, R1 is between 90% and 99% of R2and specifically is between 93% and 95% of R2, and in such embodiments,R2 is about 3 inches (e.g., 3 inches plus or minus 0.05 inches). In aspecific embodiment, R1 is between 80% and 90% of R2 and specifically isbetween 83% and 85% of R2, and in such embodiments, R2 is about 2 inches(e.g., 2 inches plus or minus 0.05 inches). In a specific embodiment, R1is between 70% and 80% of R2 and specifically is between 73% and 75% ofR2, and in such embodiments, R2 is about 1.25 inches (e.g., 1.25 inchesplus or minus 0.05 inches).

It should be noted that openings 40 and 42 are distinct from themounting and pin-receiving openings located within hub 32. In theembodiment shown, centroids of openings 40 and 42 (one centroid 56 ofopening 42 is labeled in FIG. 2 as an example) are located such that thedistance from the center point of end cap 30 to the centroids ofopenings 40 and 42 is greater than greatest distance from the centerpoint of end cap 30 to the center of the outermost one of the mountingholes. In particular embodiments, the centroids of openings 40 and 42are outwardly positioned such that the radial distance from the centerpoint of end cap 30 to each of the centroids of openings 40 and 42,shown for example as R3, is at least 35% of the outer radius R1. Inother embodiments, the centroids of openings 40 and 42 are outwardlypositioned such that the R3 is between 40% and 90% of the outer radiusR1.

In various embodiments, spokes 34 and 36 are formed from a single,solid, continuous and contiguous piece of material, such as a metalmaterial. In such embodiments, upper and lower surfaces of spokes 34 and36 define the upper and lower most surfaces of the end cap at thelocation of the spokes, such that openings 40 and 42 define openings toaccess the central cavity 22 of hole saw 10, as discussed above. Inspecific embodiments, hub 32, spokes 34 and 36 and rim 38 are formedfrom a single, solid, continuous and contiguous piece of rigid material,such as a metal material. In various embodiments, end cap 30 may be madefrom any suitable rigid material, including metals such as steel,stainless steel, plastics, ceramics, etc.

Referring to FIG. 3, another embodiment of a hole saw end cap, such asend cap 60, is shown. End cap 60 is substantially the same as end cap 30except as discussed herein. End cap 60 includes spokes 64 and 66extending from a hub 62 to rim 68. In general, spokes 64 and 66 arethicker in the circumferential direction than the spokes of end cap 30,and rim 68 is thicker in the radial direction than the rim of end cap30. However, in another embodiment, the circumferential thicknesses ofspokes 64 and 66 is constant along the radial length of the spoke.

In the embodiment shown in FIG. 3, openings 70 are substantially smallerin area than openings 72 which is the result, at least in part, of theincreased circumferential thickness of spokes 66. In variousembodiments, the area of openings 70 are less than 80% of the area ofopenings 72, and more specifically between 20% and 60% of the area ofopenings 72. In a specific embodiment, the area of openings 70 is lessthan 40% of the area of openings 72. In a specific embodiment, end cap60 has a diameter of 4 inches and is shaped to include one or more ofthe various relative opening and metal measurements, discussed above.

Referring to FIG. 4, another embodiment of a hole saw end cap, such asend cap 80, is shown. End cap 80 is substantially the same as end cap 30except as discussed herein. In general (and in contrast to end caps 30and 60), end cap 80 includes 4 or more radially extending spokes 82 thatare substantially symmetrical about a radial axis 84 that bisects eachspoke 82. In the specific embodiment shown, end cap 80 includes fiveradially extending spokes 82 that are evenly spaced around hub 86.

The clockwise and counterclockwise facing surfaces of spokes 82 alongwith radial outward facing surfaces of hub 86 and radially inward facingsurface of hub 86 define a plurality of openings 90. The symmetry andeven spacing of spokes 82 form openings 90 that all have the same shapeas each other. Further, each opening 90 is symmetrical about a radialaxis 92 bisecting each opening 90. Further, spokes 82 have a taperedshape such that the circumferential thickness of each spoke increases asthe distance toward rim 88 increases. In another embodiment, thecircumferential thicknesses of spokes 82 are constant along the radiallength of the spoke. In another embodiment, spokes 82 are tapered suchthat the circumferential thicknesses of spokes 82 decreases along thespoke as the distance toward rim 88 increases.

In various embodiments, the thickness, T1, of spokes 82 in the axialdirection (e.g., z-axis), shown by axis 96, may vary along the radial orcircumferential length of spoke 82. For example, in various embodiments,T1 may increase along the spoke as the distance toward rim 88 increases,and in some such embodiments, T1 may reach a maximum adjacent rim 88. Asanother example, in various embodiments, T1 may increase in thecircumferential decrease as the distance towards radial axis 84increases, and in some such embodiments, T1 may reach a maximum in thecircumferential direction at the center of spoke 82 along axis 84. Invarious embodiments, the variation of T1 in the radial orcircumferential direction may allow for an even lower weight end cap 80.In various embodiments, end cap 80 includes any of the different openingsize percentages, opening to material percentages, weights, etc.discussed herein.

Referring to FIGS. 5-7, additional embodiments of a hole saw end cap,such as end caps 100, 102 and 104, are shown. End caps 100, 102 and 104have the same five spoke design as end cap 80, but have differing and/orsmaller outer diameters than that of end cap 80. In the design of eachof end caps 100, 102 and 104, the length of spokes 82 and the size ofopenings 90 is decreased relative to the sizes of the same portions ofend cap 80 to account for the lower diameter of the end caps. In variousembodiments, any of the end cap designs, design features, dimensions,relative sizes, etc. of any of the embodiments discussed herein may beincorporated in to an end cap for a hole saw of any diameter. In variousembodiments, the end cap designs discussed herein may be utilized forhole saws having diameters of 1 inch, 1½ inches, 1¾ inches, 2 inches, 2½inches, 2 9/16 inches, 3 inches, 4 inches, 6 inches, etc.

Referring to FIG. 8, another embodiment of a hole saw end cap, such asend cap 110, is shown. End cap 110 is substantially the same as end cap80 except as discussed herein. End cap 110 includes four spokes 112.Similar to the spokes of end cap 80, spokes 112 are symmetrical about abisecting radial axis of the spoke. Spokes 112, hub 114 and rim 116define four openings 118. Further, the arrangement of spokes 112 andopenings 118 define a pattern such that end cap 110 is radiallysymmetric.

As shown in FIG. 8, openings 118 are relatively large and sized suchthat end cap 110 has a relatively low weight and provides the variousfunctions discussed above. In various embodiments, openings 118 have alarge circumferential length. In various embodiments, openings 118 havean arc length of between 40 degrees and 80 degrees, specifically between50 degrees and 60 degrees, and more specifically of about 55 degrees(e.g., 55 degrees plus or minus 1 degree). In the embodiment shown, thearc lengths of openings 118 are measured between ends of openings 118prior to the beginning of the curved end surfaces. In variousembodiments, openings 118 are defined by an inner radius, R3, and anouter radius, R4. In various embodiments, R4 is between 105% and 150% ofR3, specifically between 110% and 130% of R3, and more specifically isbetween 115% and 125% of R3.

Referring to FIG. 9, another embodiment of a hole saw end cap, such asend cap 130, is shown. End cap 130 is substantially the same as end cap60 except as discussed herein. End cap 130 includes spokes 64 and 66extending outward from hub 62. In this embodiment, end cap 130 does notinclude an outer rim (such as rim 68 shown in FIG. 3). In thisembodiment, spokes 64 each include an outer section 132, and spokes 66each include an outer section 134. In effect outer sections 132 and 134increase the length of spokes 64 and 66 respectively such that the totalouter diameter of end cap 130 is substantially same as the outerdiameter of similarly structured end cap having an outer rim. In theparticular embodiment shown, outer sections 132 and 134 each have outermost edges 136 and 138, respectively, that each have the same radius ofcurvature as each other such that edges 136 and 138 lie on the samecircular path as each other. As will be understood in this embodiment,the cylindrical sidewall of the hole saw is coupled to outer sections132 and 134 at edges 136 and 138.

It should be understood that the figures illustrate the exemplaryembodiments in detail, and it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for the purpose of description onlyand should not be regarded as limiting.

Further modifications and alternative embodiments of various aspects ofthe invention will be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only. The construction and arrangements, shown in thevarious exemplary embodiments, are illustrative only. Although only afew embodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Someelements shown as integrally formed may be constructed of multiple partsor elements, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. The order or sequence of any process, logicalalgorithm, or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes andomissions may also be made in the design, operating conditions andarrangement of the various exemplary embodiments without departing fromthe scope of the present invention.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is in no way intendedthat any particular order be inferred. In addition, as used herein thearticle “a” is intended to include one or more than one component orelement, and is not intended to be construed as meaning only one.

For purposes of this disclosure, the term “coupled” means the joining oftwo components directly or indirectly to one another. Such joining maybe stationary in nature or movable in nature. Such joining may beachieved with the two members and any additional intermediate membersbeing integrally formed as a single unitary body with one another, orwith the two members and any additional member being attached to oneanother. Such joining may be permanent in nature or alternatively may beremovable or releasable in nature. Various embodiments of the inventionrelate to any combination of any of the features, and any suchcombination of features may be claimed in this or future applications.Any of the features, elements, or components of any of the exemplaryembodiments discussed above may be utilized alone or in combination withany of the features, elements, or components of any of the otherembodiments discussed above.

In various exemplary embodiments, the relative dimensions, includingangles, lengths and radii, as shown in the Figures are to scale. Actualmeasurements of the Figures will disclose relative dimensions, anglesand proportions of the various exemplary embodiments. Various exemplaryembodiments extend to various ranges around the absolute and relativedimensions, angles and proportions that may be determined from theFigures. Various exemplary embodiments include any combination of one ormore relative dimensions or angles that may be determined from theFigures. Further, actual dimensions not expressly set out in thisdescription can be determined by using the ratios of dimensions measuredin the Figures in combination with the express dimensions set out inthis description. In addition, in various embodiments, the presentdisclosure extends to a variety of ranges (e.g., plus or minus 30%, 20%,or 10%) around any of the absolute or relative dimensions disclosedherein or determinable from the Figures.

What is claimed is:
 1. A hole saw end cap, comprising: a hub; a rimdefining an outer radius of the end cap; a plurality of spokes extendingradially outward from the hub toward the rim; and a plurality ofopenings formed within the end cap, one of the plurality of openingslocated between each adjacent pair of the plurality of spokes andlocated radially between the hub and the rim; wherein each of theplurality of spokes are curved in a clockwise direction; wherein the rimincludes a radially inward facing edge defining an inner radius of theend cap.
 2. The hole saw end cap of claim 1, wherein the inner radius ofthe end cap is between 90% and 99% of the outer radius of the end cap.3. The hole saw end cap of claim 1, wherein the outer radius of the endcap is about 3 inches.
 4. The hole saw of claim 1, wherein the pluralityof spokes is at least four spokes, and the plurality of openings is atleast four openings formed within the end cap, wherein each spoke isspaced from an adjacent spoke by one of the plurality of openings. 5.The hole saw end cap of claim 1, wherein the plurality of spokes of theend cap comprise a first pair of spokes and a second pair of spokes,wherein each spoke in the first pair of spokes is a mirror image of theopposing spoke, and wherein each spoke in the second pair of spokes is amirror image of the opposing spoke.
 6. The hole saw end cap of claim 1,wherein the spokes have a tapered shape such that a circumferentialthickness of each spoke increases as a distance from the radially inwardfacing edge increases.
 7. The hole saw end cap of claim 1, wherein eachspoke comprises a clockwise-facing surface and a counterclockwise-facingsurface, both extending radially from the hub to the radially inwardfacing edge, wherein the clockwise-facing surface of each spoke is aconcave surface, and the counterclockwise-facing surface of each spokeis a convex surface.
 8. The hole saw end cap of claim 1, furthercomprising a plurality of drive pin holes, the drive pin holespositioned on the hub and configured to receive the drive pins of anarbor of a driving device.
 9. A hole saw end cap, comprising: a hub; arim defining an outer perimeter of the end cap; a first pair of opposingspokes extending radially outward from the hub toward the rim; a secondpair of opposing spokes extending radially outward from the hub towardthe rim; and a first pair of openings defined within the end cap, one ofthe first pair of openings located between one of the first pair ofopposing spokes and an adjacent one of the second pair of opposingspokes and located radially between the hub and the rim; and a secondpair of openings defined within the end cap, one of the second pair ofopenings located between one of the first pair of opposing spokes and anadjacent one of the second pair of opposing spokes and located radiallybetween the hub and the rim; wherein each of the first pair of opposingspokes and the second pair of opposing spokes are curved in a clockwisedirection.
 10. The hole saw end cap of claim 9, the rim furthercomprising: a first pair of radially inward facing edges that at leastpartially define the first pair of openings; and a second pair ofradially inward facing edges that at least partially define the secondpair of openings; wherein the first pair of radially inward facing edgesand the second pair of radially inward facing edges are defined by afirst radius.
 11. The hole saw end cap of claim 10, wherein the outerperimeter of the end cap defines a second radius and wherein the firstradius is between 90% and 99% of the second radius.
 12. The hole saw endcap of claim 10, wherein the first pair of radially inward facing edgesand second pair of radially inward facing edges are aligned curvedsurfaces and each have the same radius of curvature as each other. 13.The hole saw end cap of claim 9, wherein the first pair of openings aresmaller than the second pair of openings.
 14. The hole saw end cap ofclaim 9, wherein the first pair of opposing spokes each include aconcave clockwise facing surface and a convex counterclockwise facingsurface.
 15. The hole saw end cap of claim 14, wherein a length of theconcave clockwise facing surface is less than a length of the convexcounterclockwise facing surface.
 16. The hole saw end cap of claim 9,further comprising a central hole located in a center of the hub andextending through the hub, wherein the central hole is configured tocouple the hub to an arbor of a driving device.
 17. A hole saw,comprising: a sidewall comprising cutting teeth on a first end of thesidewall and a second end opposite the first end; an end cap coupled tothe second end of the sidewall, the end cap comprising: a hub; a centralhole located in a center of the hub and extending through the hub,wherein the central hole is configured to couple the hub to an arbor ofa driving device; and a rim defining an outer perimeter of the end cap;a first pair of opposing spokes extending radially outward from the hubtoward the rim; a second pair of opposing spokes extending radiallyoutward from the hub toward the rim; and an arbor coupled to the endcap, wherein when the arbor is rotated by a driving device, the arborrotates the sidewall through the spokes to rotate the cutting teeth onthe sidewall; wherein each of the first pair of opposing spokes and thesecond pair of opposing spokes are curved in a clockwise direction. 18.The hole saw of claim 17, the end cap further comprising: a first pairof openings defined within the end cap, one of the first pair ofopenings located between one of the first pair of opposing spokes and anadjacent one of the second pair of opposing spokes and located radiallybetween the hub and the rim; a second pair of openings defined withinthe end cap, one of the second pair of openings located between one ofthe first pair of opposing spokes and an adjacent one of the second pairof opposing spokes and located radially between the hub and the rim; afirst pair of radially inward facing edges that at least partiallydefine the first pair of openings; and a second pair of radially inwardfacing edges that at least partially define the second pair of openings.19. The hole saw of claim 18, wherein the first pair of radially inwardfacing edges and the second pair of radially inward facing edges aredefined by a first radius and wherein the outer perimeter of the end capdefines a second radius and wherein the first radius is between 90% and99% of the second radius.
 20. The hole saw of claim 17, furthercomprising a central hole located in a center of the hub and extendingthrough the hub, wherein the central hole is configured to couple thehub to the arbor of the driving device.